Question 322702
How many pairs of integers (x,y)   are there such that x^2-y^2 = 2400^2 ? 

x^2 - y^2 = 2400^2 = 5760000
we know that x is greater than y
x could be positive or negative and so could y
x y
+ + x would need to be larger than y
+ - x would be larger than y
- + x would have to be greater in magnitude (absolute value) than y
- - x would have to be greater in magnitude (absolute value) than y
4 pairs